Safety starting device for gas-engines.



PATENTED FEB. 6

A. S. JOHNSON. SAFETY STARTING DEVICE FOR GAS ENGINES.

APPLICATION FILED MAY 14, 1904.

2 SHEETS-SHEET 1.

PATENTED FEB. 6, 1906.

A; S. JOHNSON. SAFETY STARTING DEVICE FOR GAS ENGINES.

APPLIOATION FILED MAY 14, 1904.

2 SHEETS-SHEET "2.

.zo'releasing said device should the crank be UNITED STATES PATENT OFFICE.

ALVIN s. JOHNSON, OF- MINNEAPOLIS; MINNESOTA, ASSIGNOR F ONE- FOURTH IO F. J. MOORE, F MINNEAPOLIS, MINNESOTA. I

SAFETY STARTING DEVICE FOR GAS-ENGINES.

No. 811,928. I Specification of Letters Patent. Patented Feb. 6; 1906.

Application filed May 14.1904. Serial No. 207,898.

To all whom it may concern:

Be it known that I, ALVIN S. JOHNSON, of ""nneapo'lis, Hennepin county, Minnesota ave invented certain new and useful Imrovements in Safety Starting Devices for as-Engines, ofwhich thefollowing is a specification.

My invention relates to gas-engines, and articularly to that ty e used on automo- IO iles; and the object o my invention is to provide means for preventing injury to the operator in case the engine should start backward or kick back. and revolve the crankshaft and hand turnin -crank in the opposite r 5 direction from that in which the operator is turning the hand-crank.

removable to permit access to the locking g mechanism.

The plate 11 is loosely mounted on the sleeve 7 and turns free] thereon when the hand crank is manipu ated. A series of ratchet-teeth 13 are provided on the outer 6o end of the sleeve 7 between the plates 1.1 and 12 on the hand-crank, and these teeth form a ratchet-wheel that is fixed with respect to p the hand-crank, and the shaft 2 has a second sleeve 14 concentric with the sleeve 7 and fit- 65 ting snugly between it and theshaft and provided at its outer end with a pin 15, that enters a slot 16 in the end of-the shaft and locks the two partsv to ether. The plate 12 fits over the outer en of the sleeve 14 and when 70 he invention consists generally in prosecured to the part 9 locks-the said sleeve viding a locking device between the handmly in place on the crank-shaft. A camcrank and shaft andmeans for automatically ring 17 is provided on the sleeve 14, having shoulders or sto s 18 upon opposite sides, and these shoul ers are engaged by a aw-l 7 5 19, pivoted on a pin 20 between the p ates 11 and 12. This pawl drops by gravity upon the surface of the cam-ring 17 and engaging one of the shoulders 18 automatically locks the hand-crank on the shaft.

Aclick21 is pivoted on the pawl 19 and normally held in engagement with the ratchetteeth 13 by a spring 22, which also draws the click and pawl together and holds the latter on the cam-surface. As shown in Figs. 5 and 8 5 6, the click is pivoted on the pawl at a point intermediate to its pivot and the end that engages the shoulder 18, and the ratchetwhirled backward by the backward revolution o;f,the crank-shaft.

Further, the i'nvenion consists generally in various constructions and combinations, all 25 as hereinafter described, and particularly pointed out in the claims.

In the accompanying drawings, forming part of this specification, Figure 1 is a side view of a safety starting device embod ing my invention. Fig. 2 is a front view 0 the same. Fig. 3 is a sectional view on the line 11. n of Fig. 5. Fig. 4 is a sectional detail view on the line m 'm of Fig. 1. Fig. 5 is a section on the line a: m of Fig. 3, showing the 3 5 .mechanism in its locked position. Fig. 6 is a similar view showin the mechanism in its unlocked position. lg. 7 is a sectional view in detail on the line y y of Fig. 3. Fig. 8 is a section on the line 2 z of Fig. 7.

4o In the drawings, 2 represents a gas-engine crank-shaft of ordinaryconstruction, and 3 is a portion of an automobile car-or bod through which the crank-shaft projects for convenience in starting the engine. a

4 is a plate secured to the car 3 over the shaft-opening therein and-having a; hole 5 to receive said shaft'and a slot 6 in the edge of said hole. A sleeve 7 is fitted over theend of said shaft and within the hole 5 and has a ;0 key 8, that enters the slot 6 and locks the-said sleeve a ainst revolution. A hand-crank 9 is provi ed, havin a suitable handle 10 .and plates 11 and 12, that are secured to the art 9 by screws or other suitable-means an are shaft and start the engine the click will slide over the ratchet-teeth. If-the crank-shaft starts backward and transmits its movement to the crank, the pressure on the pawl 19 will be transmitted to the click-21, and as it can- 5 not move backward over the ratchet teeth it will throw the pawl out of engagement with .the shoulder with which it may be in contact, and the crank-shaft can then be revolved backward without affecting the hand-crank rod or endangering thelimbs of the operator.-

I prefer to provide some means for locking the pawl after its automatic disengagement from the cam-ring shoulder, and I therefore provide a pin 23, mounted in ,the plate 12 and yieldingly held in engagelnent with the surface of the a .l by a spring 24. As soon as the pawl is thrown out of engagement with the shoulder the pin will be shot in behind the pawl, as indicated in Fi 6, and will prevent it from dropping bac upon the camring. When the operator desires to couple the/ hand-crank and shaft, he will withdraw the pin 23 and allow the pawl to drop 1) gravity upon the cam-ring and then turn t e end of the crank until the pawl engages one of the shoulders 18, when the crank will again be coupled with the eration can be repeated.

It will be noted that the locking of the crank-arm on the shaft is entirely for automatic, that it is only necessa the operator to turn the crank towar the right and it will lock itselfon the shaft, and upon starting the engine if there should be any kicking back of the crank-shaft, with a locking and untendency to whirl the crank backward, it will instantly become automatically released from the shaft, and no possible injury can come to the o erator.

I c aim as my invention- 1. The combination, with a gas engine crank-shaft, of an arm loosely mounted thereon, mechanism for locking said arm on said shaft when it is turned in one direction, mech 'anism for tripping said locking mechanism upon arm, and means for holding said locking mechanism in its unlocked or inoperative position after being tripped, for the purpose specified.

shaft, and the starting opthe reverse movement of said shaft and I 2-. In a device of the class described, the combination, with a crank-shaft having stops or shoulders, of a loosely-mounted crank-arm, a pawl thereon arranged to engage said shoulders when said arm is turned in one direction, mechanism for tripping said pawl upon the reverse movement of said arm and shaft, and a springressed in arranged to drop behind said paw and ho d it in its unlocked position.

3. The'combination, with an automobilecar body, of a crank-shaft projecting therethrough, two sleeves arrangedon said shaft, one within the other, th outer sleeve being fixed and having a series of external ratchetv teeth, the inner sleeve being connecte with said shaft and provided with suitable stops or shoulders, a crank-amp loosely mounted on said sleeves, a pawl pivoted on said'arm and adapted to bearu on said movable sleeve and engage said shou ders whensaid arm is turned in one direction, and a click pivoted on said pawl between its pivot and ointof en agement with said shoulders an engaging the teeth of said ratchet to trip said pawl i when said shaft and arm are turned in the other direction.

In witness whereof I have hereunto set my RICHARD PAUL, M. HAGERTY. 

